﻿/*
 * Authors:
 *   钟峰(Popeye Zhong) <zongsoft@qq.com>
 *
 * Copyright (C) 2010-2013 Zongsoft Corporation <http://www.zongsoft.com>
 *
 * This file is part of Zongsoft.Plugins.
 *
 * Zongsoft.Plugins is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * Zongsoft.Plugins is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Zongsoft.Plugins; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

using System;
using System.Collections.Generic;

namespace Zongsoft.Plugins.Parsers
{
	public class PluginPathParser : Parser
	{
		#region 公共方法
		public override Type GetValueType(ParserContext context)
		{
			if(string.IsNullOrWhiteSpace(context.Text))
				return null;

			//处理特殊路径表达式，即获取插件文件路径或目录
			if(context.Text.StartsWith("~"))
				return typeof(string);

			var expression = PluginPath.Parse(PluginPath.PreparePathText(context.Text));
			var node = context.Node.Find(expression.Path);

			if(node != null && node.ValueType != null)
				return Reflection.MemberAccess.GetMemberType(node.ValueType, expression.Members);

			return null;
		}

		public override object Parse(ParserContext context)
		{
			if(string.IsNullOrWhiteSpace(context.Text))
				return null;

			//处理特殊路径表达式，即获取插件文件路径或目录
			if(context.Text == "~")
				return context.Plugin.FilePath;
			else if(context.Text == "~/")
				return System.IO.Path.GetDirectoryName(context.Plugin.FilePath);

			var mode = ObtainMode.Auto;
			var text = PluginPath.PreparePathText(context.Text, out mode);

			if(string.IsNullOrWhiteSpace(text))
				throw new PluginException($"Missing argument of the path parser.");

			return context.PluginContext.ResolvePath(text, context.Node, mode, context.MemberType);
		}
		#endregion
	}
}
